Work proposed for the coming year includes extension of the testing of the thromboresistance properties of the grafted and heparin-bound polymer samples. The grafting technique and reactions leading to heparinization are still poorly controlled and more work must be done to perfect them. Work will be done on the grafting and heparinization of additional polymers of interest by similar methods, and studies will be carried out to determine ease of extraction of heparin from the heparinized polymers by water, saline solution, and blood serum. More work will be done in developing both in vitro and in vivo tests for thrombus formation on the treated polymers.